dbus-sdr: update attribute naming rules

update sensor command names to use `Lower Camel Case`.

Change-Id: I1c21591e8dccee62f41841f2889bda205c2a5e8b
Signed-off-by: George Liu <liuxiwei@ieisystem.com>
diff --git a/include/dbus-sdr/sdrutils.hpp b/include/dbus-sdr/sdrutils.hpp
index b52351d..dcbaf59 100644
--- a/include/dbus-sdr/sdrutils.hpp
+++ b/include/dbus-sdr/sdrutils.hpp
@@ -308,9 +308,9 @@
     voltage = 0x02,
     current = 0x03,
     fan = 0x04,
-    physical_security = 0x5,
+    physicalSecurity = 0x5,
     processor = 0x07,
-    power_unit = 0x09,
+    powerUnit = 0x09,
     other = 0x0b,
     memory = 0x0c,
     buttons = 0x14,